The BT change happened in 2005, at least on the A3/A4. I don't know if any A6 C5 ever got BT factory installed. You will need a VAG-COM or dealer check the part number of the device at ID #77. If there is not device responding it's likely that you don't have BT. If the part number of the device responding at ID #77 starts with 8P0 and doesn't end in D or E or has no letter at the end then you might be lucky and have BT but it's not enabled.DonNiger said:So, does every A6 from 2004 has a bluetooth already installed. I have the RNS-E installed by the factory, but how can I but it into action.
I'm from Europe.